1. Field of the Invention
The present invention relates to a dielectric ceramic composition capable of low-temperature firing, a dielectric ceramic comprised of the composition, an electronic device and a communication device including the ceramic.
2. Description of the Related Art
Recently, as electronic devices employed in a communication device such as a mobile phone are miniaturized with high performance at a high frequency range, demands for devices capable of exhibiting a high frequency property abruptly increase.
Particularly, for a mobile communication device such as a mobile phone which is in high demand, high frequency band called quasi-microwave ranging from several hundred MHz to several GHz is used. In line with that, for electronic devices such as capacitors, filters, resonators, and circuit boards employed in the mobile communication devices, properties applicable to the high frequency band are required.
As materials having a high dielectric constant in the microwave range, Bi—Zn—Nb based oxide is known.
Patent Document 1 discloses Bi—Zn—Nb based dielectrics exhibiting excellent dielectric properties (high relative dielectric constant (∈r) and high Qf value). However, in Patent Document 1, the firing temperature still exceeds 900° C. and further reduction of the temperature is required for the purpose of electronic devices that Ag is used as an internal conductor. Further, for the Bi—Zn—Nb based dielectrics, it is known that bending strength is generally low.
In view of the above, in order for further improving performance of the Bi—Zn—Nb based dielectrics, it is required to increase the bending strength while maintaining excellent dielectric properties.
Patent Document 1: Japanese Patent No. 4494881